The proposed studies deal with regulation of inflamatory responses in the lung. Specifically, the chemotactic factor inactivator will be examined in lung homogenates and in extracts of neutrophils and alveolar macrophages. The physical-chemical properties and subcellular location of the inactivator in lung homogenates, neutrophils and alveolar macrophages will be assesseed and compared with serum-associated CFI. The immunochemical relationship between these inactivators will be explored. The role of the inactivator in the control of immunologically mediated acute inflammatory reactions in blood vessels and in the lung will also be examined.